I had an 03 6.oh that I bought new and ran for 230000 kms. My 6.4 has 85000 kms. The 6.4 is far superior and in a totally different league!!!!!!!!

With DPF it is a pig on fuel, but...

Find a mod friendly dealer, get a programmer with some mild tunes(do your homework, as all are not created equal), do a DPF delete, and have the best of everything - gobs of power, great mileage, and did I mention - lots of power and great mileage???

If you are going to run a 6.4 with DPF intact, the case for a V10 sounds very convincing though - the posters above are right on the money. The 'emissions complexity' of all brands of new diesels almost negate any benefit of owning one...